I have a Cat that's almost 17 he's skinny I can't get weight on him he's always eating Canned food and even Senior Dry Food he's back bone when you pet him I was just wondering what I can give him to fatten him up some ... I need to get him checked out from a vet I think just to have blood work done

Welcome to the forum cfrabbitry04, the first thing to do is bring your senior kitty into the vet for a full exam, geriatric blood panel including T4 Thyroid check and a urinalysis. Once the test results come back, you will know more about what is going on with the health of your boy, you can then decide about treatments if necessary.

The weight loss is common with a number of health issues, could also be normal age related for a senior. Increasing the canned food and adding some extra protein like cooked or raw chicken breast is always a good idea. For a male cat, especially, it is important to limit or completely remove, if possible, the dry food without reducing the amount he is eating. A high quality meat protein based food that has no grain, corn or filler will be greatly beneficial to preserving his health. Male cats are at higher risk of urinary tract issues and dry food puts cats into a state of dehydration which is why drinking water & having extra moisture in the form of canned/raw food is very important.

let us know how the visit goes.

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Even for people it is hard to keep weight on as one ages....how many fat 85 y.o. do you see? Not many, is my observation, most are pretty thin. Muscles weight more than fat, and as body ages, muscle tone is lost. If your cat is healthy and does not have a severe deteriorating condition, e.g. failing kidneys=drinking lots of water, your cat could live into it's 20s. My neighbour's cat just died at age 22. Take him to the vet and have his health evaluated. Let us know how it goes. All the best!